Tomorrow I will be brewing a hoppy IPA and I have thought of using gypsum to make does hop really pop. I always use PH 5.2 with RO water with great results. This time I really want to make the hops come through. Should I mix both PH 5.2 and Gypsum or just stick with one of them? Any thoughts?

You can do some quick searching on this forum to find popular brewery's water profiles. I remember seeing Sierra Nevada and Green flash on here. I've used this calculator to find out what type of water I have, and what I need to add to get the water I want. Should help.

Two teaspoons gypsum in a 10 gallon batch would add about 120 ppm, which should give you the effect you want. Generally though, I'd say NOT to make mineral additions unless you know what's in the water at the beginning.

5.2 just adds a bunch of sodium to the water and doesn't really improve brewing in most cases. But in this brewer's case, starting with RO water could actually get a benefit since 5.2 adds a bit of buffering that keeps the pH from dropping too low when the calcium level is increased. The target sulfate level in brewing water is highly subjective and up to the brewer's taste. Bringing the sulfate level to 120 ppm may be a good start, but I find that boosting it to around 300 ppm is pleasing in an IPA.

Since gypsum can be added directly to the boil kettle and would not be needed in the mash because RO water is used, I recommend that 5.2 be deleted from the mashing water and add most of the gypsum directly to the kettle with a little added to the tun to help reduce beerstone formation. The calcium reacts with oxalate in the mash to reduce beerstone potential.

As AJ Delange likes to say, 5.2 works great for brewers that don't check their mash pH and doesn't work at all for brewers that do check pH. In other words, its snake oil.

Thanks everyone. I will be brewing tomorrow and after what I have read I am going with some calcium chloride and gypsum. Will put the info in beers ugh and calculate what I need to add for my brew. Will let you know how it turns out.

I ended up using the 5.2 and added 4 Tbsp of Gypsum to the boil. Yates it before pitching yeast and do far had great flavor. I decided to split the batch and ferment with two different yeast WLP001 and WLP002.